Mechanical telephone



(No Model.)

0. M. RADPORD.

MECHANICAL TELEPHONE.

No. 411,058. Patented Sept. 17, 1889.

Z d Q V w :Z w n u ll k M llli .0 M a)? 4 l s\\ \\\\\\\k \b M x J N. PETERS. Phom-Li|hogmphcn Washmgiwn, D. Cv

UNITED STATES PATENT OFFICE.

CASS M. RADFORD, OF CONCORD, NEIV HAMPSHIRE, ASSIGNOR TO HIMSELF, FRANK L. BLOOD, OF GROTON, AND FREEMAN EMMONS, OF \VAKEFIELD,

MASSACHUSETTS.

MECHANICAL TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 411,058, dated September 17, 1889.

Application filed June 14, 1889. Serial No. 314,211. (No model.)

To all whom it may concern:

Be it known that I, CASS M. RADFORD, of Concord, in the county of Merrimac, State of New Hampshire, have invented a certain new and useful Improvement in Mechanical Telephones, of which the following is a d escription sufficiently full, clear, and exact to enable any person skilled in the art or science to which said invention appertains to make and use the same, reference being had to the accompanying drawings, formingpart of this specification, in which- Figure l is afront elevation of my improved telephone, the wires being shown as broken off; Fig. 2, a vertical transverse section of the same, taken 011 line so as in Fig. 1; and Fig. 3, an enlarged view of the button detached.

Like letters and figures of reference indicate corresponding parts in the different figures of the drawings. 7

My invention relates to an improvement in mechanical telephones, whereby more than one wire may be employed with a single transmitter; and it consists in certain novel features, as hereinafter fully set forth and claimed, the object being to produce a simpler, cheaper, and more effective device of this character than is now in ordinary use.

Thenature and operation of the improvement will be readily understood by all conversant with such matters from the following explanation.

In the drawings, A represents the supporting-plate, B the wires, and O the transmitter.

The plate A is preferably constructed of wood and of a shape suitable to be readily adjusted against the wall of a room.

The transmitter 0 consists of awooden box rectangular in cross section, secured to the face of the plate A.

A circular opening I) is formedin the front Wall d of the box 0, and a metallic diaphragm f, consisting of a cone-shaped plate of the usual form in telephones of this class, is secured to the front wall (1 around the opening I), in the usual manner.

A button D, (see Fig. 3,) provided with a head 1 and laterally-elongated loop or shank h, is disposed in the apex of the cone-shaped plate A above the box 0, and is provided with v a centrally-arrauged vertical slot 19, through which the wires B pass. The slot or opening 19 is lined with lead q orsimilar non-resonant substance, and a series of pins 0' project through the front of the block on into said slot, in position to respectively engage the wires B. Each pin is independently pivoted by its outer end to one of a series of camlevers r, pivoted to the block at and adapted to force said pins inward against the wires, pressing them against the non-resonant lining q of the slot 13, and serving to deaden or prevent them from vibrating. A guide-bar w is secured at the upper end of the plate, said wires B passing through the bar, and from thence diverging in the directions desired. In the use of my improvement the wires are drawn sufliciently taut to hold the buttonhead i firmly against the diaphragm f in the usual man nerof telephones of this class. The diaphragm is employed both in receiving and transmitting in the ordinary way. When it is desired to communicate with any particular point, the levers o of the wires running to other places are depressed, forcing said wires against the slot-lining q and preventing the sound from passing over them beyond the block on, the vibrations on the remaining wire being interrupted. As the block m is disposed a considerable distance from the button, the wires with which the cam-pins are engaged vibrate between said block and button.

By thus disposing the wires that the same sound-waves cause them to vibrate in unison the apparatus is rendered especially valuable for telephoning long distances. Moreover, as any desired number of wires may be employed with a single transmitter, the device is particularly applicable for use in hotels and similar establishments.

Having thus explained my invention,whatI claim is 1. In a mechanical telephone, the button D, comprising the headt' and laterally-elongated loop h, substantially as described.

2. In a mechanical telephone, a transmitter, a button disposed in the diaphragm thereof and provided with an elongated shank, and a series of conducting wires secured within the transmitter and passing through said button-shank, substantially as described.

3. In a mechanical telephone, a transmitter provided with a cone-shaped metallic diaphragm, a button secured in the apex thereof and provided with an elongated shank or loop, a series of conducting-wires passing through said loop, and .mechanism for independently deadening or preventing said wires from vibrating, substantially as described.

4. In a mechanical telephone, abody-plate, a transmitter secured thereto and provided with a cone-shaped diaphragm, a button for said diaphragm having a laterally-elongated loop-shank, conductingwires secured within said transmitter and passing through said loop, a bar on the body-plate provided with a wire-slot having a non-resonant lining, and cam-levers on the bar for forcing the wires against said lining, substantially as and for the purpose set forth.

5. In a mechanical telephone, abody-plate, a transmitter having a cone-shaped metallic diaphragm, a button disposed in the apex thereof and provided with a laterally-elongated loop, conducting-wires passing through said loop and in contact therewith, a bar secured to the body-plate and provided with a wire-slot having a non-resonant lining, pins projecting into said slot, and cam-levers pivoted to said pins, substantially as and for the purpose set forth.

6. In a mechanical telephone provided with a series of conducting-wires, a slotted bar through which the wires pass, said slot being lined with a non resonant substance, and mechanism for forcing said wires into engagement with the slot-lining, substantially as and for the purpose set forth.

7. In a mechanical telephone, the bar m,

provided with the wire-slot p, having the non CASS M. RADFORD.

Witnesses:

LORREN W. JAMES, DANIEL B. DONOVAN. 

